Introduction to special steel

There is no unified definition and concept for special steel. It is generally considered that special steel refers to steel with special chemical composition (alloying), special process production, special structure and performance, and can meet special needs. Compared with ordinary steel, special steel has higher strength and toughness, physical properties, chemical properties, biocompatibility and process properties.

The definition of special steel in China is close to that of Japan and EU. Special steel is divided into three categories: high quality carbon steel, alloy steel and high alloy steel spring (alloy element is more than 10%). Among them, alloy steel and high alloy steel account for 70% of the special steel output. The main steel types are excellent special carbon structural steel, carbon tool steel, carbon spring steel, alloy spring steel, alloy structural steel, ball bearing steel, alloy tool steel, high alloy tool steel, high-speed tool steel, stainless steel, heat-resistant steel, high-temperature alloy, precision alloy, electric thermal alloy, etc. At present, there are nearly 2000 special steel grades and about 50000 specifications in the world. In addition to various types of special steel, it also shows different characteristics from ordinary steel in specifications. In addition to plate, tube, wire, strip, bar and profile, there are composite materials, surface alloying materials, surface treatment materials, precision forging materials, precision castings, powder metallurgy products, etc.